1.0 ABSTRACT

The membrane separation experiment was conducted by using the Membrane Test Unit

(Model : TR14) which has been designed to demonstrate the technique of membrane

separations which has become highly popular as they provide effective separation

without the use of heating energy as in distillation processes. The main objective of this

experiment was to study a characteristics on four different types of membranes. The four

types of membrane used in this experiment were membrane 1 : AFC99 (Polyamide Film),

membrane 2 : AFC40(Polyamide Film), membrane 3 : CA 202 (Cellulose acetate) and

membrane 4 : FP100(PVDF).Membrane separation can be classified by pore sizes such

as membrane 1 is for nanofiltration(NF), membrane 2 is for ultrafiltration (UF),

membrane 3 is for reverse osmosis(RO) and membrane 4 is for microfiltration(MF). Each

membrane have a different maximum inlet pressure (bar). For membrane 1 the maximum

inlet pressure is 18 bars, for membrane 2 is 12 bars, the membrane 3 is 10 bars while the

membrane 4 is 8.5 bars. Therefore, the maximum working pressure for the system is set

at 20 bars. After allowing the system to run for 5 minutes, the sample was collected from

the permeate sampling port and the weight of permeates every 1 minute for 10 minutes

were taken. The procedure was repeated for all membranes. From the data taken, the

graph of permeate weight versus time was plotted. The graph showed that the permeate

weight is increasing as the time increase. The highest amount for permeates during 10

minutes is 10096.61 g which is for membrane 4 while the least amount for permeates is

164.37 g which is for membrane 3. Although there might be some errors that occurred in

this experiment, we can conclude that the experiment is successful.

2.0 INTRODUCTION

The membrane technology covers all process engineering measures for the transport of

substances between two fractions with the help of permeable membranes. In this

relatively separation process, the membrane acts as a semipermeable barrier and

separation occurs by the membrane controling the rate of the movement of various

molecules between two liquid phase, two gas phases, or a liquid and a gas phase. The two

fluid phases are usually miscible and the membrane barrier prevents actual, ordinary

hydrodynamic flow. Important applications of membrane technology include drinking

water by reverse osmosis filtrations in the food industry, the recovery of organic vapors

such as gasoline vapor recovery and the electrolysis for chlorine production. But also in

wastewater treatment, the membrane technology is becoming increasingly important.

This Membrane Test Unit (Model: TR 14) has been designed to demonstrate the

technique of membrane separations without the use of heating energy as in distillation

processes. This type of membrane is widely used in biotechnology and process industry.

Heat sensitive materials such as fruit juices can be separated or concentrated by virtue of

their molecular weights.

This self-contained unit which coated by steel framework, it requires only connection to a

suitable electricity supply and a normal cold water supply to be fully operational. It

consists of a feed tank, a product tank, a feed pump, a pressure regulator, a water bath,

and a membrane test module. All parts in contact with the process fluid are stainless steel,

PTFE, silicone rubber or nitrile rubber. The unit comes with a high pressure feed pump

for delivering the feed to the membrane unit at the desired flow rate and pressure. The

retentate line can be either returned to the feed tank or straight to the drain. Appropriate

sensors for flow, pressure and temperature are installed at strategic locations for process

monitoring and data acquisitions.

The unit consists of a test module supplied with four different membranes namely the

reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF) and microfiltration (MF)

membranes.

Comparison for 4 types of membranes

Reverse osmosis (RO) is a  filtration method that removes many types of large molecules

and ions from solutions by applying pressure to the solution when it is on one side of a

selective membrane. The solute is retained on the pressurized side of the membrane and

the pure solvent is allowed to pass to the other side. Nanofiltration describes a process of

water purification that remove contaminats from the water to produce clean, clear and

pure water. Ultrafiltration is a separation process using membranes with pore sizes in the

range of 0.1 to 0.001 micron.  Typically, ultrafiltration will remove high molecular-

weight substances, colloidal materials and organic and inorganic polymeric molecules. 

Low molecular-weight organics and ions such as sodium, calcium, magnesium chloride

and sulfate are not removed.  Microfiltration is a process which removes contaminants

from a fluid (liquid and gas) by passage through a microporos membrane. A typical

microfiltration membrane pore size range is 0.1 to 10 micrometers (µm). Microfiltration

is fundamentally different from reverse osmosis and nanofiltration because those systems

use a pressure as a means of forcing water to go from low pressure to high pressure.

Microfiltration can use a pressurized system but it does not need to include pressure.

3.0 AIMS

To study a characteristic on four different types of membrane.

4.0 THEORY

A membrane is a selective barrier that permits the separation of

certain species in a fluid by combination of sieving and sorption

diffusion mechanism. Separation is achieved by selectively passing one

or more components of a stream through the membrane

while retarding the passage of one or more other components.

Membrane processes are characterized by the fact that a feed stream is divided into 2

streams: retentate and permeate. The retentate is that part of the feed that does not pass

through the membrane while the permeate is that part of the feed that does pass

through the membrane. The optional "sweep" is a gas or liquid that is used to help

remove the permeate. The component of interest in membrane separation is known as

the solute. The solute can be retained on the membrane and removed in the retentate or

passed through the membrane in the permeate.

Some advantages of membrane separation are less energy-intensive since they do not

require major phase changes, do not demand adsorbents or solvents which may be

expensive or difficult to handle and the equipment simplicity and modularity which

facilitates the incorporation of more efficient membranes. The particular advantage of

membrane separation processes is that it operate without heating and thus are

energetically usually lower than conventional thermal separation processes. This

separation process is purely physical and due to its gentle separation, the use of both

fractions (permeate and retentate) is possible.

5.0 APPARATUS AND MATERIALS

Apparatus

i. SOLTEQ Membrane Test Unit (Model : TR14)

ii. 4 different types of membrane - membrane 1 : AFC99 (Polyamide Film)

- membrane 2 : AFC40(Polyamide Film)

- membrane 3 : CA 202(Cellulose acetate)

- membrane 4 : FP100(PVDF)

iii. Container

iv. Digital weighing balance

v. Stopwatch

Material

i. 100g Sodium chlorideii. Water

6.0 METHODOLOGY / PROCEDURE

1. The general start-up procedures were performed.

2. The experiment was started for membrane 1. Valves V2, V5, V7, V11 and V15 were opened.

3. The maximum working pressures was set to 20bars, by switching on the plunger pump (P1) and slowly valve V5 was closed. The pressure value at pressure gauge was observed and the pressure regulator was adjusted to 20bars.

Warning : Make sure valve V2 is opened.

4. Valve V5 was opened. Then, the maximum inlet pressure was set to 18bars for membrane 1 by adjusting the retentate control valve (V15).

5. The system was allowed to run for 5minutes. The sample from permeate sampling port were collected and the sample was weighing using digital weighing balance. The weight of permeates were recorded every 1 minute for 10 minutes.

Note : Valve V19 was opened and simultaneously valve V11 was closed to collect sample.

6. Step 1 to 5 were repeated for membrane 2, 3 and 4. The respective sets of valves were opened and closed and the membrane maximum inlet pressure was adjusted for every membrane.

7. The graph of permeate weight versus time was plotted.

7.0 RESULTS

Membrane 1

Pressure (bar) Time (min) Weight (g)

18.00 1.00 42.50

18.00 2.00 83.06

Membrane Open valves (step 2)

Sampling valves

Retentate control valve

Membrane maximum inlet pressure (bar)

1 V2, V5, V7, V11 and V15

Open V19 and close V11

V15 18

2 V2, V5, V8, V12 and V16

Open V20 and close V12

V16 12

3 V2, V5, V9, V13 and V17

Open V21 and close V13

V17 10

4 V2, V5, V10, V14 and V18

Open V22 and close V14

V18 8.5

18.00 3.00 123.98

18.00 4.00 164.41

18.00 5.00 206.33

18.00 6.00 247.18

18.00 7.00 288.52

18.00 8.00 329.32

18.00 9.00 370.88

18.00 10.00 412.32

Membrane 2

Pressure (bar) Time (min) Weight (g)

12.00 1.00 65.75

12.00 2.00 120.41

12.00 3.00 178.7212.00 4.00 235.01

12.00 5.00 290.88

12.00 6.00 347.52

12.00 7.00 404.4812.00 8.00 461.52

12.00 9.00 518.57

12.00 10.00 575.05

Membrane 3

Pressure (bar) Time (min) Weight (g)

10.00 1.00 28.6810.00 2.00 43.5110.00 3.00 59.44

10.00 4.00 75.87

10.00 5.00 91.65

10.00 6.00 107.8910.00 7.00 124.25

10.00 8.00 140.52

10.00 9.00 157.28

10.00 10.00 174.37

Membrane 4

Pressure (bar) Time (min) Weight (g)

8.50 1.00 519.02

8.50 2.00 1026.38

8.50 3.00 1532.60

8.50 4.00 2053.65

8.50 5.00 2565.23

8.50 6.00 3059.56

8.50 7.00 4075.57

8.50 8.00 5570.85

8.50 9.00 7582.30

8.50 10.00 10096.61

GRAPH OF PERMEATE WEIGHT VS TIME

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.000

2000

4000

6000

8000

10000

12000

Membrane 4Membrane 3Membrane 2Membrane 1

8.0 DISCUSSION

This experiment has been done to fulfil the objective which is to perform a characteristic

study on four different types of membrane. In doing this experiment, the apparatus used

to accomplish the objective is SOLTEQ Membrane Test Unit (Model: TR14). This unit

has been designed to demonstrate the technique of membrane separations as it provides

separation in effective way without using heat energy.

In this unit, there are four types of membrane which each of them is differ with each

other. The four membranes reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF)

and lastly microfiltration (MO) membranes respectively while in the case of membrane

type are AFC99, AFC40, CA202 and FTP100 respectively. Every type of this membrane

has its own characteristics which differ in each other as shown in table below :

Membrane

type

Material

Max

pH

range

Max

pressur

e

(bar)

Max

temperature

(℃¿

Apparent

Retention

character

Hydro

philicity

Solvent

resistance

1 AFC99 Polyamide

Film

1.5-12 64 80 99% NaCl 3 + +

2 AFC40 Polyamide

Film

1.5-9.5 60 60 60% Ca

Cl2

4 + +

3 CA202 Cellulose

Acetate

2-7.25 25 30 2000 MW 5 +

4 FP100 PVDF 1.5-12 10 80 100,000M

W

1 + + +

From the table above, its show that each membrane have different characteristic with

each other. The first characteristics are based on its material. Membrane I and membrane

2 were made up from the same element which is Polyamide Film while the other two

membranes were made up from cellulose acetate and PVDF. Polyamide film (membrane

1 and 2) is known as its permeability to water and its relative impermeability to various

dissolved impurities including salt ions and other small non-filterable molecules.

Membrane 3 is made of cellulose acetate which has an extremely low binding

characteristic that made it ideal for protein and enzyme filtrations. The material that

membrane 4 is made of is  polyvinylidene difluoride (PVDF). PVDF is a material that

can provide high protein and nucleic acid binding capacity. In terms of maximum pH

range, membrane 1 and 4 have the maximum capacity of range while membrane 2 and 3

were the least. While in properties of maximum operating pressure, membrane 4 shows

the least operation while membrane 1 is the most maximum operating unit in term of

pressure.

The other characteristics of the membrane is apparent retention character with membrane

1 rated as 99% NaCl rejection, membrane 2 with 60% CaCl2 rejection, membrane 3 with

2,000 MWCO and membrane 4 with 100,000 MWCO. Furthermore, the membranes are

characterized with their own hydrophilicity level. Hydrophilic membrane is a membrane

that has an attractive response to water and can readily adsorb water. This allows the

material to be wetted forming a water film or coating on the surface of the membrane.

Hydrophobic membrane is the opposite of it. Usually hydrophilic membrane has more

charge than hydrophobic membrane. Membrane 3 has the highest hydrophilic property

followed by membrane 2, 1 and 4. These mean that membrane 4 has the highest

hydrophobic property and usually known as hydrophobic membrane.

In doing this experiment, approximately 100mL sodium chloride has been used as the

reagent (feed). Each membrane has been set to a certain maximum pressure inlet for a

safety regulation so as not to exceed the maximum operation pressure of the membrane.

Then, the sample from permeate was collected for 10 minutes. In each 1 minute interval,

the weight of permeate was recorded. After the 10 minutes past, these steps were carried

out again for the others membranes unit.

For membrane 1, the weight of permeate collected after 10 minutes is 412.32g. For

membrane 2 is 575.05g while for membrane 3 is the lowest which is 174.37g. Lastly, for

membrane 4 the weight of permeate collected after 10 minutes is the highest which is

10096.61g. All the data got from this experiment was recorded in table in result section.

From the result, it shows that when the time increase the weight of permeate will also

increase for all four membranes. Permeate is actually a part of the feed stream that passed

through the membrane, while a part of the feed that did not pass through the membrane is

called the retentate. In the graph plotted, it shows that there are different permeation rate

for each of membrane, with membrane 4 has the highest permeation rate followed by

membrane 2, I and lastly 3. Thus, permeates moves faster through membrane 4 and

slower in membrane 3. The high permeation rate of membrane 4 is most probably due to

its hydrophobic property, whereas the low permeation rate of membrane 3 is most

probably due to its hydrophilic property. The membrane separates a wide range of

particle sizes ranging from mono ions to macromolecules.

In doing this experiment, the result get may be not 100% accurate although it follows the

theory. The error could be due to the lack of attention in doing the experiment, such as

not alert in taking the record in 1 minute’s interval and not accurate in adjusting the

maximum inlet pressure. This experiments can be improve by followed the

recommendations suggested at recommendation sections.

9.0 CONCLUSION

The objective of this experimentis to study a characteristic on four different types

of membranes by using 100g of sodium chloride. The highest weight of a permeate is

10096.61g, which is for the membrane 4 while the least weight of a permeate is 174.37g

which is for membrane 3. Due to the theory, the weight of permeate for each membrane

will be different because of the difference of the maximum inlet pressure for each

membrane. From the result taken, we can also conclude that the separation process will

occur fastest in the membrane 4 and slowest at the membrane 3. From the graph that had

been plotted, it showed that the permeate weight is increasing with time. In conclusion,

based on the objective above, the experiment is concluded as successful.

10.0 RECOMMENDATIONS

i. Ensure that before starting the experiment, the maximum working pressure for the

system is 20 bars because if the pressure exceeded 20 bars, the membrane will

break while if it is lowest than 20 bars, it will not be suitable for each membrane

used in this system.

ii. Ensure that each particular membrane has its correct inlet pressure at the

beginning of each experiment for each different membrane because if the inlet

pressure is not correct for that particular membrane, it will not be suitable for the

membrane thus effecting the result of the experiment.

iii. While taking the weight of the permeate by using the digital weighting balance,

the value will increase rapidly so to make sure that the accurate values can be

taken, two or more students are needed to record the result so that the average

value among them can be recorded as a result.

iv. When collecting the sample from permeates sampling port, make sure that a big

container is being used to support the volume of the sample thus to avoid the

sample from spill out in order to get more accurate weight of permeates.

v. The system should be run in more than 5 minutes so that the system and

membrane maximum inlet pressure is more stabilized in order to get the accurate

weight of the permeates.

vi. During collecting the sample, the sampling valves should be open and close simultaneously so that there is no interruption occurduring collecting the sample from permeates sampling port.

vii. The average weight of permeates should be calculated by taking the weight of

permeates three times in order to get more accurate value of weight of permeates.

viii. Do not operate the pump in dry condition therefore the valve 2 is needed to be

ensure to be opened because if the pump is operating at dry condition, some break

down can occur.

11.0 REFERENCES

i. Richard M. Felder & Ronald W. Rousseau, third edition, Elementary Principle of

Chemical Processes

ii. Lab Manual of Chemical Engineering UiTM (CHE 523), SOLTEQ Membrane

Test Unit (Model : TR14)

iii. Membrane Separation Process, n.d.. Available from :

<http://en.wikipedia.org/wiki/

Membrane_technology#Membrane_separation_processes>. [ 18 October 2014]

iv. SOLTEQ Membrane Test Unit (TR:14), n.d.. Available from :

<https://www.google.com.my/url?

sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB4QFjAA&url=http%3A

%2F%2Fwww.solution.com.my%2Fpdf

%2FTR14(A4).pdf&ei=VDpDVILlBuTKmAXG-

YKwAg&usg=AFQjCNGbxYmZ46q-8pAJWsOB_Duto4lhMA>. [ 18 October

2014]

v. Pressure Driven-Pressure Separation Technologies,n.d.. Available from :

<http://www.itrcweb.org/miningwaste-guidance/to_membrane_sep.htm>. [ 19

October 2014]

vi. Lab Technician of FKK Pilot Plant, Encik Jamil.

12.0 APPENDIX

Picture of Membrane